Add Codecov secret to .github/workflows/tests-on-pr.yml to use Codecov

.codecov.yml

@@ -1,34 +1,14 @@
-# codecov can find this file anywhere in the repo, so we don't need to clutter
-# the root folder.
-#comment: false
-
-codecov:
-  notify:
-    require_ci_to_pass: no
-
 coverage:
   status:
-    patch:
+    project:  # more options at https://docs.codecov.com/docs/commit-status
       default:
-        target: '70'
-        if_no_uploads: error
-        if_not_found: success
-        if_ci_failed: failure
-    project:
-      default: false
-      library:
-        target: auto
-        if_no_uploads: error
-        if_not_found: success
-        if_ci_failed: error
-        paths: '!*/tests/.*'
-
-      tests:
-        target: 97.9%
-        paths: '*/tests/.*'
-        if_not_found: success
-
-flags:
-  tests:
-    paths:
-      - tests/
+        target: auto # use the coverage from the base commit, fail if coverage is lower
+        threshold: 0%  # allow the coverage to drop by
+
+comment:
+  layout: " diff, flags, files"
+  behavior: default
+  require_changes: false
+  require_base: false  # [true :: must have a base report to post]
+  require_head: false  # [true :: must have a head report to post]
+  hide_project_coverage: false # [true :: only show coverage on the git diff aka patch coverage]

.github/workflows/tests-on-pr.yml

@@ -14,3 +14,5 @@ jobs:
       project: diffpy.utils
       c_extension: false
       headless: false
+    secrets:
+      CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}